The renal dopamine-like ingredients in the claimed compositions are described in U.S. Pat. Nos. 4,197,297 or 4,265,889. The .beta.-blocking agents are old in the art and are described here by their accepted generic names. H. J. Sanders, Chemical and Engineering News, July 12, 1982 page 26 described the development, mechanism of action and utility of .beta.-blocking agents. No prior art mention of the claimed compositions is known to the applicants.
Each of the components of the composition of this invention has been described in the literature to be useful combined with diuretics, for example see European patent application No. 22,330 published Jan. 14, 1981 and R. T. Owen, Pharmacy International 1981, 17-21. EP No. 22,330 describes the specifically acting renal dopaminergic agents of Formula I to have a synergistic natriuretic effect with thiazide diuretics but not with diuretics acting at sites other than the distal convoluted tubules. No increase in renal filtration rate was reported.
The Owen article discloses that .beta.-blockers combined with diuretics are a useful combination in treating various cardiovascular conditions but that synergism cannot be demonstrated reproducibly.